From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id A8547385F02A for ; Thu, 2 Apr 2020 08:44:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A8547385F02A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tdevries@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B246FAA73; Thu, 2 Apr 2020 08:44:13 +0000 (UTC) Subject: Re: [PATCH][gdb] Expand symbolless symtabs using maint expand-symtabs To: Tom Tromey Cc: gdb-patches@sourceware.org References: <20200329160050.GA24275@delia> <87eet70z32.fsf@tromey.com> From: Tom de Vries Autocrypt: addr=tdevries@suse.de; keydata= xsBNBF0ltCcBCADDhsUnMMdEXiHFfqJdXeRvgqSEUxLCy/pHek88ALuFnPTICTwkf4g7uSR7 HvOFUoUyu8oP5mNb4VZHy3Xy8KRZGaQuaOHNhZAT1xaVo6kxjswUi3vYgGJhFMiLuIHdApoc u5f7UbV+egYVxmkvVLSqsVD4pUgHeSoAcIlm3blZ1sDKviJCwaHxDQkVmSsGXImaAU+ViJ5l CwkvyiiIifWD2SoOuFexZyZ7RUddLosgsO0npVUYbl6dEMq2a5ijGF6/rBs1m3nAoIgpXk6P TCKlSWVW6OCneTaKM5C387972qREtiArTakRQIpvDJuiR2soGfdeJ6igGA1FZjU+IsM5ABEB AAHNH1RvbSBkZSBWcmllcyA8dGRldnJpZXNAc3VzZS5kZT7CwKsEEwEIAD4WIQSsnSe5hKbL MK1mGmjuhV2rbOJEoAUCXSW0JwIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAh CRDuhV2rbOJEoBYhBKydJ7mEpsswrWYaaO6FXats4kSgc48H/Ra2lq5p3dHsrlQLqM7N68Fo eRDf3PMevXyMlrCYDGLVncQwMw3O/AkousktXKQ42DPJh65zoXB22yUt8m0g12xkLax98KFJ 5NyUloa6HflLl+wQL/uZjIdNUQaHQLw3HKwRMVi4l0/Jh/TygYG1Dtm8I4o708JS4y8GQxoQ UL0z1OM9hyM3gI2WVTTyprsBHy2EjMOu/2Xpod95pF8f90zBLajy6qXEnxlcsqreMaqmkzKn 3KTZpWRxNAS/IH3FbGQ+3RpWkNGSJpwfEMVCeyK5a1n7yt1podd1ajY5mA1jcaUmGppqx827 8TqyteNe1B/pbiUt2L/WhnTgW1NC1QDOwE0EXSW0JwEIAM99H34Bu4MKM7HDJVt864MXbx7B 1M93wVlpJ7Uq+XDFD0A0hIal028j+h6jA6bhzWto4RUfDl/9mn1StngNVFovvwtfzbamp6+W pKHZm9X5YvlIwCx131kTxCNDcF+/adRW4n8CU3pZWYmNVqhMUiPLxElA6QhXTtVBh1RkjCZQ Kmbd1szvcOfaD8s+tJABJzNZsmO2hVuFwkDrRN8Jgrh92a+yHQPd9+RybW2l7sJv26nkUH5Z 5s84P6894ebgimcprJdAkjJTgprl1nhgvptU5M9Uv85Pferoh2groQEAtRPlCGrZ2/2qVNe9 XJfSYbiyedvApWcJs5DOByTaKkcAEQEAAcLAkwQYAQgAJhYhBKydJ7mEpsswrWYaaO6FXats 4kSgBQJdJbQnAhsMBQkDwmcAACEJEO6FXats4kSgFiEErJ0nuYSmyzCtZhpo7oVdq2ziRKD3 twf7BAQBZ8TqR812zKAD7biOnWIJ0McV72PFBxmLIHp24UVe0ZogtYMxSWKLg3csh0yLVwc7 H3vldzJ9AoK3Qxp0Q6K/rDOeUy3HMqewQGcqrsRRh0NXDIQk5CgSrZslPe47qIbe3O7ik/MC q31FNIAQJPmKXX25B115MMzkSKlv4udfx7KdyxHrTSkwWZArLQiEZj5KG4cCKhIoMygPTA3U yGaIvI/BGOtHZ7bEBVUCFDFfOWJ26IOCoPnSVUvKPEOH9dv+sNy7jyBsP5QxeTqwxC/1ZtNS DUCSFQjqA6bEGwM22dP8OUY6SC94x1G81A9/xbtm9LQxKm0EiDH8KBMLfQ== Message-ID: Date: Thu, 2 Apr 2020 10:44:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <87eet70z32.fsf@tromey.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-19.8 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Apr 2020 08:44:16 -0000 On 01-04-2020 21:45, Tom Tromey wrote: >>>>>> "Tom" == Tom de Vries writes: > > Tom> When trying to expand the partial symtab for hello.h: > Tom> ... > Tom> $ gdb -batch \ > Tom> -iex "set language c" \ > Tom> a.out \ > Tom> -ex "maint expand-symtabs hello.h" \ > Tom> -ex "maint info psymtabs" > Tom> ... > Tom> we in fact find that the partial symtab has not been expanded: > Tom> ... > Tom> { psymtab hello.h ((struct partial_symtab *) 0x27cf070) > Tom> readin no > Tom> ... > > Does this matter, though? > I thought include psymtabs like these were kind of placeholders. > Right, but the includer symtab they're pointing towards are also not expanded. Concretely, it does matter for dwarf assembly test-cases, in the sense that this patch allows me to have the symtab effect of setting a breakpoint in a certain file, without actually setting the breakpoint, which means there's no need to flesh out the .debug_line section in detail, or indeed even create the file. [ I mentioned this patch as a prerequisite for a dwarf assembly test-case here : https://sourceware.org/pipermail/gdb-patches/2020-March/167152.html ] Furthermore, I found this problem originally not with include psymtabs, but with this type of one-DIE CUs: ... <0>: Abbrev Number: 1 (DW_TAG_compile_unit) DW_AT_stmt_list : 0x0 <10> DW_AT_low_pc : 0x400430 <18> DW_AT_high_pc : 0x40045b <20> DW_AT_name : ../sysdeps/x86_64/start.S <24> DW_AT_comp_dir : /home/abuild/rpmbuild/BUILD/glibc-2.26/csu <28> DW_AT_producer : GNU AS 2.31.1 <2c> DW_AT_language : 32769 (MIPS assembler) ... which I get in every exec on openSUSE Leap 15.1. In that case, the problem means that "maint expand-symtabs" doesn't expand the symtab, in violation of the "maint expand-symtabs" documentation, while also being inconsistent with -readnow which does create a symbolless symtab. I used the include psymtabs as test-case and running example because it reproduces on all platforms in a standard test-case. > Tom> Fix this by passing a NULL symbol_matcher and lookup_name to > Tom> expand_symtabs_matching in maintenance_expand_symtabs, and skipping the call > Tom> to recursively_search_psymtabs if symbol_matcher == NULL and > Tom> lookup_name == NULL. > > Could this code use map_symtabs_matching_filename instead? > I can see how that would help with "maint expand-symtabs ", but still "maint expand-symtabs" would not expand the partial symtab for ../sysdeps/x86_64/start.S. Thanks, - Tom > I guess I'm not super fond of turning the reference arguments to > pointers, unless there's really no other way.